Man, this is all pointless specerlating...
Only way to know how things would have played out is to peer into that parallel universe of ours where Bush suddenly decided, "Nope, not signing it."
Where would we be right now? Same as today, or everyone speaking Farsi?
That's mind numbingly stupid. Not only are you giving Muslim extremists more power than they ever had in this fantasy, you didn't even guess the right Muslims.